bobbins



2 SheetS-She et 1.

(N0 Model.)

7 E. ROBBINS.

TACKLE BLOCK.

Patented Oct. 12, 1886.

Wil /7611660 gzzt z a 2 Sheets-Sheet '2. E. ROBBINS.

(No Model.)

- TACKLE'BLOGK.

No. 350,771. P

atented Oct. 12, 1886.

Tag, 0?

UNiren rates Fries.

ATENT ELISHA ROBBINS, OF XVORCESTER, MASSACHUSETTS, ASSIGXOR TO HENRY\V. ROBBINS, OF SAME PLACE.

TACKLE SPECIFICATION forming part of Letters Patent No. 350,771, datedOctober 12, 1886.

Application filed May 21, 1886.

To all whont it may concern.-

Be it known that I, ELISHA ROBBINS, of the city and county ofXVorcester, inthe Connnonwealth of Massachusetts, have invented a newand useful Improvement in TackleBlochs for Hoisting Purposes, of whichthe following is a specification.

The object of my device is to reduce the friction of the sheave in itsbearing on the pin or IO axle, and also avoid friction or chafing of thesheave against the inner sides of the shell. I attain this by making agroove or recess encircling the pin the length of the bearing of thesheave in which is laid a series eta-utifriction rolls encircling thegroove, and on which the sheave takes its bearing, to be revolvedtogether in the block, the rolls being free to revolve with the sheaveround the pin in the groove. To avoid any friction or chafzo ing of thesheave against the inner sides of the shell,the sheave is made slightlyconvex on the sides from its bearing to its outer rim, and, besidesthis, the anti-friction rolls are helpfulin this respect.

Rcferringtothedrawingsaccoinpanyingthis specification, Figure 1, Sheet1, represents an edge view of the block and sheave adjusted therein.Fig.2 represents a vertical sectional view of the same, showing theadjustment of 0 the sheave on the anti-fiiction-roller pin. Fig.

' 3, Sheet 2, represents the pin or axle, showing the series of rolls inthe groove just filling it flush on a line with the ends of the pin.Fig.

4 represents the pin, showing the form of the 5 groove, the rolls takenout. Fig. 5 is a sec- 1 Serial No. 202,868. (No model.)

tional end view of the pin, taken at the ends of the rolls, showing theends of the rolls as they encircle the groove of the pin. Fig. 6

is a vertical sectional viewof the pin and sheave through the center ofthe axle, showing 0 a roll at top and bottom.

Similar letters indicate similar parts in the several drawings.

A denotes the block in which the sheave B is adjusted, and C denotes thepin, and (I (Z d the series of anti-friction rolls inserted in thegroove or recess E of the pin. These rolls are laid in the groove whenthe parts are put to gether,and constitute the hearing of thesheavc inthe block.

I am aware the anti-friction rolls have been used in tackle blocks andin wagon-wheels and pulleys in various formsprior to my invention. Itherefore do not claim the anti-friction rolls as such, broadly, in atackle-block; but

That I do claim as my invention or device, and desire to secure byLetters Patent, is-

I11 a pulley-block, the combination of the block, the sheave, pin 0,having the circumferential groove or recess of the width of the 60sheave, and the anti-friction rollers encircling the reduced portion ofthe pin and filling the groove flush with the periphery ofthe pin, theanti-friction rollers forniingthe bearing of the sheave, allsubstantially as described.

ELISIIA ROBBINS.

\Vitnesses:

JONA. LUTHER, MIRICK H. CowDEN.

